The present invention relates to an intraocular lens which is adapted to be seated in the eye adjacent the periphery of the iris, for example, in the anterior chamber, the posterior chamber or partly in the anterior chamber and partly in the posterior chamber, after the removal of a natural lens. The invention also relates to a method of inserting an intraocular lens into an eye.
It has been found that the insertion of an intraocular lens is by far the best solution to correcting vision after cataract surgery. The proper implantation of an intraocular lens always involves the risk of damage to the eye particularly during the insertion process as well as at a later time if the intraocular lens dislocates or must be removed or replaced.
To place the lens in the eye adjacent the periphery of the iris, the surgeon ordinarily makes an incision or opening in the cornea which aligns with the pupil, and the surgeon passes the lens through the opening. In many of the more recent lenses the position-fixation members of the lens are either no wider than the lens body, or are flexible and can be bent to pass through an opening which is about the same size as the lens body or can be snaked through such opening. Accordingly, the minimum length of the opening which must be made is ordinarily determined by the diameter of the lens body, or optic, which ordinarily has a circular periphery and which is substantially rigid, being formed of a material such as, for example, methylmethacrylate and having a configuration which provides the desired optical characteristics. It is, of course, desirable to make the opening in the cornea as small as possible to minimize the risk of damage to the eye.
Other types of intraocular lenses are known which are flexible and which are secured to the iris. Such lenses can not be seated in the eye adjacent the periphery of the iris. One such lens described in U.S. Pat. No. 4,172,297 has a position-fixation flange surrounding the light-focusing lens body or optic for securing to the iris and thus the lens is not adapted for insertion through an incision smaller than the diameter of the lens body. Another such lens described in U.S. Pat. No. 4,206,518 has a pair of wide position-fixation members extending from opposite peripheral regions of the light-focusing lens body or optic for connection to the iris and this lens also is not adapted for insertion through an incision smaller than the diameter of the lens body. Still another such lens, described in U.S. Pat. No. 4,253,199, has a peripheral lip for suturing to the ciliary body of the eye for deforming the lens body in accordance with the expansion and contraction of the ciliary body so as to change the optical characteristics of the lens body in response thereto. The lens bodies of these prior lenses are impeded by the position-fixation members integral therewith from being adapted for insertion through an incision smaller than the diameter of the lens body.